1. Field of Invention
The present invention relates generally to medical devices and methods for sealing and closing passages formed through tissue. More specifically, the present invention relates to devices for sealing or closing an opening formed through biological tissue comprising a distal or outside margin or surface, and a proximal or inside margin or surface (i.e., a wall thickness), and to apparatuses and methods for delivering such devices, to control (or prevent or stop) bleeding (or the flow of other biological fluid or tissue). The openings comprise punctures, incisions, or other openings formed through biological tissue such as blood vessels or organs.
2. Description of Prior Art
Access to arterial and venous vascular systems is necessary for intravascular surgical procedures such as cardiac catheterizations and interventional procedures such as percutaneous transluminal coronary angioplasty or stenting. These intravascular surgical procedures generally are performed by inserting a hollow needle through a patient's skin (percutaneously) and any intervening tissue into the vascular system, e.g., an artery such as a femoral artery. A guide wire may then be passed through the needle lumen into the patient's blood vessel. Once the guide wire is in place the needle may be removed, leaving the guide wire in place. An introducer sheath may be advanced over the guide wire into the vessel, e.g., in conjunction with or subsequent to a dilator. A catheter or other device utilizing the percutaneous opening may then be advanced through a lumen of the introducer sheath and over the guide wire into the desired intravascular position.
Upon completing the intravascular procedure, the catheter, introducer sheath, guide wire and other medical device components may be removed, leaving an opening in the blood vessel wall (the so-called puncture site, or arteriotomy) and the proximal tissue tract through which blood can flow to the outside (bleeding). External pressure (manual compression) may be applied to the percutaneous puncture site until clotting and wound sealing occur. This procedure, however, may be expensive and time consuming, requiring as much as an hour of a physician's or nurse's time. It is also uncomfortable for the patient, and requires that the patient remain immobilized in the operating room, catheterization laboratory, or holding area. In addition, a risk of hematoma exists from bleeding before hemostasis occurs.
Once the bleeding has stopped, an elastic bandage (pressure bandage) or sandbag is often placed over the site of the puncture; this exerts pressure so as to prevent the blood clot from being washed away by the pressure in the blood vessel which can easily happen, especially in the case of an arterial puncture. This pressure bandage or sandbag must remain in place for some time, varying from clinic to clinic from 8 to 24 hours. During the period of time that the pressure bandage is in place, the patient must remain resting in bed. After removing the pressure bandage, the patient can become mobile again. This usually means, in practice, that following a percutaneous arterial procedure, the patient must stay in the hospital for a prolonged period of time, often overnight.
This external pressure procedure (manual compression) is associated with quite a few complications which are inherent in the technique. Intense bleeding can occur in addition to pseudo-aneurysms (whereby a passage exists, via the puncture site, between the lumen of the blood vessel and a clot situated around the blood vessel (hematoma), arteriovenous fistulas (passages between the arterial and venous systems of blood vessels) and retroperitoneal hematomas can also arise. Neighboring nerves can also become compressed or traumatized from direct pressure or profuse bleeding, resulting in pain, sensation disturbances or even paralysis of the groups of muscles which are innervated by these nerves. These complications arise in approximately 1-3% of all procedures. Surgical intervention is sometimes necessary whereby the hematoma is relieved and the puncture site is sutured over (and, if required, any fistula is sealed).
Various apparatuses and devices have been suggested and are being used for percutaneously sealing a vascular puncture by occluding or approximating the margins (edges) of the puncture site (These apparatuses and devices should be known to those skilled in the art, all of which need not be specifically referenced herein). These apparatuses and devices relate to closure devices that must be manually deployed via a deployment instrument. See, e.g., U.S. Pat. No. 5,676,689, issued to Kensey et al. With respect to the prior art, the efficacy of vascular closure depends strongly on the user's ability to position the closure means accurately with respect to the puncture site while the procedure is performed blindly. The manual deployment means of such vascular closure devices (characterized by multiple user-performed steps and device manipulations) necessitates the user to develop a highly subjective “feel” or “tactile technique” to reliably position the closure device correctly.
This requirement of tactile manipulation coupled with the many user-induced procedural steps, difficulty of use, long learning curves, and low precision (of the prior art devices) has lead to a slow adoption rate for vascular closure devices among cardiac catheterization laboratories. As a result, the benefits to the patient (comfort and improved medical outcome) and to the institution (enhanced throughput and decreased costs) are compromised.